Fix terminal pty issues on Windows/mintty in cloud/influxdb login

This falls back to plain text input which will echo the password back,
but there doesn't seem to be a way around that. :-/

cmd/login_cloud.go

@@ -22,10 +22,13 @@ package cmd
 
 import (
 	"os"
+	"syscall"
 
 	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
 	"github.com/spf13/afero"
 	"github.com/spf13/cobra"
+	"golang.org/x/crypto/ssh/terminal"
 	"gopkg.in/guregu/null.v3"
 
 	"github.com/loadimpact/k6/lib/consts"
@@ -51,6 +54,8 @@ This will set the default token used when just "k6 run -o cloud" is passed.`,
   k6 login cloud`[1:],
 	Args: cobra.NoArgs,
 	RunE: func(cmd *cobra.Command, args []string) error {
+		// TODO: don't use a global... or maybe change the logger?
+		logger := logrus.StandardLogger()
 		fs := afero.NewOsFs()
 
 		k6Conf, err := getConsolidatedConfig(fs, Config{}, nil)
@@ -89,6 +94,9 @@ This will set the default token used when just "k6 run -o cloud" is passed.`,
 					},
 				},
 			}
+			if !terminal.IsTerminal(syscall.Stdin) {
+				logger.Warn("Stdin is not a terminal, falling back to plain text input")
+			}
 			vals, err := form.Run(os.Stdin, stdout)
 			if err != nil {
 				return err

cmd/login_influxdb.go

@@ -22,11 +22,14 @@ package cmd
 
 import (
 	"os"
+	"syscall"
 	"time"
 
 	"github.com/mitchellh/mapstructure"
+	"github.com/sirupsen/logrus"
 	"github.com/spf13/afero"
 	"github.com/spf13/cobra"
+	"golang.org/x/crypto/ssh/terminal"
 
 	"github.com/loadimpact/k6/lib/types"
 	"github.com/loadimpact/k6/stats/influxdb"
@@ -42,6 +45,8 @@ var loginInfluxDBCommand = &cobra.Command{
 This will set the default server used when just "-o influxdb" is passed.`,
 	Args: cobra.MaximumNArgs(1),
 	RunE: func(cmd *cobra.Command, args []string) error {
+		// TODO: don't use a global... or maybe change the logger?
+		logger := logrus.StandardLogger()
 		fs := afero.NewOsFs()
 		config, configPath, err := readDiskConfig(fs)
 		if err != nil {
@@ -80,6 +85,9 @@ This will set the default server used when just "-o influxdb" is passed.`,
 				},
 			},
 		}
+		if !terminal.IsTerminal(syscall.Stdin) {
+			logger.Warn("Stdin is not a terminal, falling back to plain text input")
+		}
 		vals, err := form.Run(os.Stdin, stdout)
 		if err != nil {
 			return err

ui/form_fields.go

@@ -21,6 +21,7 @@
 package ui
 
 import (
+	"bufio"
 	"io"
 	"os"
 	"strings"
@@ -122,6 +123,16 @@ func (f PasswordField) GetContents(r io.Reader) (string, error) {
 		return "", errors.New("Cannot read password from the supplied terminal")
 	}
 	password, err := terminal.ReadPassword(int(stdin.Fd()))
+	if err != nil {
+		// Possibly running on Cygwin/mintty which doesn't emulate
+		// pseudo terminals properly, so fallback to plain text input.
+		// Note that passwords will be echoed if this is the case.
+		// See https://github.com/mintty/mintty/issues/56
+		// A workaround is to use winpty or mintty compiled with
+		// Cygwin >=3.1.0 which supports the new ConPTY Windows API.
+		bufR := bufio.NewReader(r)
+		password, err = bufR.ReadBytes('\n')
+	}
 	return string(password), err
 }